Mirrors are exceptionally smooth pieces of glass that are supported by a highly polished, brilliant reflecting substance. Light passes through the glass and bounces off the smooth and polished rear surface. When you gaze in the mirror, the light from your face reflects off of it. That's why when you look in the mirror, you see yourself.
Mirrors have been used for security purposes since ancient times. Guard towers with moving mirrors are found at many castles around the world. Modern mirrors also can be used to provide security at events or locations where there is not enough police presence. For example, they are used by private security companies to watch over large crowds at music festivals or sports events where more officers might not be able to get through the crowd.
The quality of a mirror is important because it determines how well it will reflect light. A very reflective mirror will give a bright image while an averagely reflective one will only reflect part of the incident light.
Generally, regular glass is used for mirroring objects due to its stability and durability. However, certain objects such as clocks or jewelry may require specular (i.e. mirror-like) surfaces for proper functioning. These special mirrors are made of highly polished stainless steel or aluminum.
You might wonder why we need mirrors if everything we want to see, we already see. The answer is simple: mirrors allow us to see invisible things.
A mirror is often constructed of glass and has a gleaming metal background that reflects all light that touches it. When a mirror reflects light, an image is formed. An image is a reflection or refraction-created duplicate of an item. When reflected light rays really meet in front of a mirror, a true picture is formed. The image is as clear as day because there are no shadows due to the fact that all the light from one object reaches the mirror at the same time.
Mirrors can be used to look at themselves. This is called autofocus photography and is useful for taking pictures of objects without having to worry about positioning since the camera will find its own subject. Autofocus lenses also allow the photographer to focus on a specific part of the scene rather than having to worry about getting everything in focus at once.
When light rays reach a surface at different times, they create shadows. These shadows are what make objects visible at night or in low light conditions when using artificial lights instead of the sun. A mirror reverses the direction of light so that it hits simultaneously; therefore, it doesn't produce a shadow.
Mirrors have many uses in science. Scientists use mirrors to reflect light into dark areas where it cannot normally reach. For example, scientists have used this technique to examine parts of the human body that would otherwise be invisible in the dark.
A common mirror is made of glass that has been coated with a metal coating. Glass alone reflects a little amount of light, but the metal coating considerably increases reflectivity. The glass and metal are held together by an adhesive.
They can be used for viewing objects at a distance, as headlights for vehicles, and as solar panels for heating water or powering devices.
There are several different methods used to make mirrors. One of the oldest methods is called "lapping". In this method, a piece of metal plate is lapped (smoothed) by rubbing it against a softer material such as sand or oil. The metal is then polished using a rouge stone until it is smooth and shiny. This is the method used by most manufacturers when making mirrors for use in cars. A newer method is electroplating. In this method, a metal rod is placed into a tank containing a solution that contains elements needed to deposit metal onto the surface of the rod. An electric current is passed through the solution to deposit atoms of the desired metal onto the surface of the rod. Finally, the metal-coated rod is removed from the solution and washed thoroughly before being used in a product.
Most mirrors are made from aluminum because of its lightweight and resistance to corrosion.
Mirrors reflect mostly due to their electrical conductivity. When light strikes a mirror, the metal within (typically aluminum or silver) cancels out the electric field parallel to the mirror, causing it to shift directions and reflect away. The amount of reflection depends on the quality of the surface.
The reason we see our own faces in mirrors is that human skin is nearly 100% reflective. The fraction that isn't reflects some wavelengths and passes others. The part that doesn't pass these wavelengths goes into the color spectrum and appears darkly colored. Human skin is red because of blood cells and melanin. Melanin is a pigment which absorbs certain wavelengths of light and reflects others. Thus skin colors from yellow to black are possible. White skin is very rare unless caused by an allergy or albinism because white hair and eyes are due to lack of melanin rather than its presence. Eyes that are completely white are called blue because that color is not seen by our naked eye but by the photographer's camera lens or monitor screen. Eyes that are completely black are called hazel because they contain both brown and white fibers inside the socket. They can be found among people of African descent.
People wonder why mirrors show up empty-handed in fairy tales and folklore. It's because magic mirrors don't reflect everything; they only reflect those things you want them to reflect.
The most common mirrors are made of a plate of clear glass with a thin reflective layer on the back (the side opposite the incident and reflected light) that is protected against abrasion, tarnishing, and corrosion by a coating. The reflective layer may be aluminum or silver. The thickness of the reflective layer should be about 0.5 mm (0.02 in). Higher-quality mirrors are made of glass with a copper foil backing instead.
In addition to these two types of mirror, there are also mirrors called "flexible" or "plastic", which are now used instead of glass for certain applications. These plastic mirrors are very thin (about 100 microns thick), so they are flexible enough to be rolled up for storage or transportation. They can also be unrolled to fit into a limited space. When used as mirrors, they usually have a flat surface mounted onto a wall or window frame. They are useful where breaking glass would be dangerous because they are thin and can be mounted outside a door or into a cabinet where broken glass might be concealed.
Flexible plastic mirrors use a thin film of aluminum or silver which is deposited onto the plastic sheet using a process similar to that used for making solar cells. This allows them to reflect light like conventional mirrors but they cannot be scratched or broken like glass mirrors. They also do not break into sharp pieces like glass when struck by moving objects.
Mirrors are excellent in reflecting light rather than refracting it, so the light rays remain together and in a roughly straight path, allowing you to view the reflected item or surface. However, due to the nature of light, which is both a particle and a wave, when a mirror reflects light, there is a slight delay before the next thing that happens. This is called the "reflection lag" and it's what allows you to see your own image in a mirror.
This reflection lag varies depending on how fast you're moving toward or away from the mirror, as well as the distance between you and the mirror. If you're very close to the mirror, then the reflection lag will be very short. As you get farther away from the mirror, the reflection lag will also get longer.
However, even though the reflection lag is long at first, it will eventually catch up with you as you move further away from the mirror. Once you reach a certain point, there won't be any more room inside the gap between you and the mirror, so nothing can pass through it anymore. Even if you were to run as fast as lightning towards the mirror, you would still only be able to see yourself smile or frown after an interval of time equal to your movement speed.